Tag: fMRI

Science journalist Robin Marantz Henig is a contributing writer at The New York Times Magazine. Her next book, co-authored with her daughter Samantha Henig, is called Twentysomething: Why Do Young Adults Seem Stuck? and will be out in November.

Is regret something you accumulate in your life, piling it up as you remember an ever-increasing number of things that really could have gone better? If so, you’d think that young people would have fewer regrets than older ones, since they haven’t lived as long and haven’t missed as many chances—and if they have missed a chance at some adventure or relationship, they’re more likely to think that the chance will come around again.

But a recent study by Stefanie Brassen and her colleagues at University Medical Center Hamburg-Eppendorf in Germany suggests that young people feel more regret than old people, largely because the older people seem to be quashing those nasty feelings before the feelings overtake them. Indeed, they found that the only 60-somethings who experienced regret at the same level as 20-somethings were those who were depressed.

I think it’s worth considering, though, whether the German investigators really were tapping into regret at all, or a different aspect of youth psychology.

Brassen and her colleagues simulated regret by having her subjects play a Let’s Make a Deal-type computer game in which they opened a succession of boxes to earn cash. They could keep opening boxes and keep accumulating cash as long as they stopped before they opened the box containing a pop-out devil. If they got to the devil, the game was over and they had to give back everything they’d earned in that round.

The researchers were less interested in how many boxes the subjects opened than in how they felt about the chances they missed. After the round was over, the investigators revealed the contents of the unopened boxes. The more boxes the subjects could have opened before getting to the devil, the more regret they were expected to feel, since they could have earned even more money if they’d been just a little more daring.

By Neuroskeptic, a neuroscientist who takes a skeptical look at his own field, and beyond. A different version of this post appeared on the Neuroskeptic blog.

Brain-scanning studies may be giving us a misleading picture of the brain, according to recently published findings from two teams of neuroscientists.

Both studies made use of a much larger set of data than is usual in neuroimaging studies. A typical scanning experiment might include around 20 people, each of whom performs a given task maybe a few dozen times. So when French neuroscientists Benjamin Thyreau and colleagues analysed the data from 1,326 people, they were able to increase the statistical power of their experiment by an order of magnitude. An American team led by Javier Gonzalez-Castillo, on the other hand, only had 3 people, but each one was scanned while performing the same task 500 times over.

In both cases, the researchers found that close to the whole of the brain “lit up”—that is, showed increased metabolic activity—when people were doing simple mental tasks, compared to just resting. In one case, it was seeing videos of people’s faces; in the other, it was deciding whether stimuli on the screen were letters or numbers. Both studies made use of functional magnetic resonance imaging (fMRI), which uses powerful magnetic fields to image the brain and detect the changes in blood oxygen caused by differences in the firing rate of the cells in different areas.

There have been many thousands of fMRI papers published since the technique was developed 20 years ago. The great majority of these have produced the familiar “blob” plots showing that different kinds of mental processes engage localized activity in particular parts of the brain. Thyreau and Gonzalez-Castillo, however, were able to detect effects too small to be noticed in such neuroimaging experiments, and found that rather than isolated blobs, large swathes of the brain were involved. This doesn’t mean that everywhere responded equally to the task: the signal was stronger in some areas of the brain than in others, but there were no clear-cut divisions between “active” and “inactive” areas.

While the new results don’t overturn the localization theory as such, they do show that it’s only part of the picture. The blobs are real enough, as they show us the areas where activation is strongest, but it’s misleading to think of these areas as the only places involved in a particular task. Other activations, smaller or less consistent but no less real, are hidden under the threshold of statistical noise. fMRI experiments may just be showing us the tip of the iceberg of brain activity.